Subversion Repositories openrisc

// Copyright 2011 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package exec

import (
        "errors"
        "os"
        "strings"
)

// ErrNotFound is the error resulting if a path search failed to find an executable file.
var ErrNotFound = errors.New("executable file not found in $path")

func findExecutable(file string) error {
        d, err := os.Stat(file)
        if err != nil {
                return err
        }
        if m := d.Mode(); !m.IsDir() && m&0111 != 0 {
                return nil
        }
        return os.EPERM
}

// LookPath searches for an executable binary named file
// in the directories named by the path environment variable.
// If file begins with "/", "#", "./", or "../", it is tried
// directly and the path is not consulted.
func LookPath(file string) (string, error) {
        // skip the path lookup for these prefixes
        skip := []string{"/", "#", "./", "../"}

        for _, p := range skip {
                if strings.HasPrefix(file, p) {
                        err := findExecutable(file)
                        if err == nil {
                                return file, nil
                        }
                        return "", &Error{file, err}
                }
        }

        path := os.Getenv("path")
        for _, dir := range strings.Split(path, "\000") {
                if err := findExecutable(dir + "/" + file); err == nil {
                        return dir + "/" + file, nil
                }
        }
        return "", &Error{file, ErrNotFound}
}